Influence of pH on the electroless Ni-P plating of SiC particles

Abstract

A layer of nickel- phosphorus (Ni-P) was plated on micron sized silicon carbide (SiC) particles by using an electroless plating technique. The pH, as the most influential parameter in the plating process, was varied in two-step increments from 3 to 9 to study its effect on Ni-P deposition and its characteristics. Variations in pH levels affect both the uniformity of the Ni-P layer distribution and the phosphorus content. Depending on the pH conditions, the Ni-P coating may exhibit various structures, transitioning from poly-crystal, micro-crystal, nano-crystal to amorphous states as a result of differing phosphorous contents. XRD and SEM with EDS analysis on the SiC particles were performed before and after the plating process. The research findings indicate that a lower pH led to inadequate adhesion and coverage of the Ni-P layer onto the SiC particles, whereas a higher pH facilitated the formation of an even Ni-P layer. Nonetheless, the phosphorus content exhibited a decreasing trend as the pH values increased.